Kernel Panic - Not Syncing: VFS: Unable to Mount Root FS on Unknown-Block(0,0)

Support
1

good day
i have a vps with Contabo and their support is literally non existant
my vps is running an almalinix v8.8.0 - it doesnt boot with the latest kernel 4.18.0-477.27.2.el8_8.x86_64 and i have to select an older one 4.18.0-477.21.1.e18_8 for it to boot

I deleted the faulty kernel with yum remove kernel-4.18.0-477.27.2.el8_8.x86_64 but it continues to show in my console when the vps boots

update-initramfs -u -k 4.18.0-477.27.2.el8_8.x86_64 : command not found
update-grub : command not found

how to proceed ?! i dont care about the last kernel

Screenshot 2023-11-06 102050
Screenshot 2023-11-06 102050714×366 11.6 KB

2

error

Screenshot 2023-11-04 172237
Screenshot 2023-11-04 172237816×418 7.16 KB

3

The kernel is in multiple packages. See rpm -qa kernel\*
In other words, there may be kernel-core, kernel-modules, etc still in for 477.27.2.el8_8.
If so, the boot entry is probably from them, not from/by the kernel package.

Note though that some packages, like kernel-tools* and kernel-headers are not install_only and thus should not be removed.

I think that the first tool is now dracut and the second grub2-mkconfig, but you can
look whether you have /boot/loader/entries/*.conf
If there is a file for 477.27.2, then you can remove it for starters.

4

thank you … i have these - what should i do next? i have 0 idea about linux

Screenshot 2023-11-06 111243

5

We can actually show a shorter list:

dnf rq --installonly --latest=1

If all packages on the output are about 477.27.2, then you can use that list:

dnf remove $(dnf rq --installonly --latest=1)
6

they are mixed … i think Kernelcare from immunify360 updates it till last kernel - i unloaded the kernel care but it is still showing like this

image

7

Well, it shows latest installed for each package and since you did already remove kernel, for that package the latest is different.

You can do manually:

dnf remove kernel-core-0:4.18.0-477.27.2.el8_8.x86_64 kernel-modules-0:4.18.0-477.27.2.el8_8.x86_64 kernel-modules-extra-0:4.18.0-477.27.2.el8_8.x86_64

PS. Screenshots, bitmap images, are not a convenient way to post information. Not when one can copy-paste text. One can format text to be preformatted (aka “with code tags”).

8

i removed all these packages and my server was able to reboot in the 4.18.0-477.21.2.el8

should i retry to upgrade it ? and if yes how ?!

9

I upgraded through WHM
it is working now
thank you !

image

10

Server (no VM) fails to reboot with this issue if I ‘dnf update’ to

Kernel: Linux 4.18.0-513.18.1.el8_9.x86_64
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)

I was able to follow this thread and remove the offending kernel and go back to:

Kernel: Linux 4.18.0-513.11.1.el8_9.x86_64

which does boot.

Any idea what the issue might be and how to fix it? I don’t use WHM

Thanks.

11

I also meet this issue today, and I found /boot/initramfs-4.18.0-513.18.1.el8_9.x86_64.img is 0 with command

ll /boot/initramfs-*

what I do is rebuild the initial ramdisk image with command

dracut -f /boot/initramfs-4.18.0-513.18.1.el8_9.x86_64.img 4.18.0-513.18.1.el8_9.x86_64
12

Just back in town, I auto dnf-update nightly but not reboot, apparently it self corrected

I ran ll /boot/initramfs-* and it showed 1, rebooted fine, so not sure why the issue in the first place.

However this is very good to know and i will be running ll /boot/initramfs-*, and dracut if needed, in the future before re-booting after a kernel update.

Thanks

13

Also hardware server owner (and root) here…

KP happened to me twice only while working wired directly to server machine(via fuckkdecumlet).

Sued them. FUCKERS

FUCK ssd